Many systems and methods for locating mobile terminals are known in the art. A common feature of such systems, and corresponding locating methods, is to exploit parameters or characteristics that are intrinsic to cellular communications constituted, for instance:                by an identifier of the base radio station which is able to exchange information with the mobile terminal (serving stations),        by electromagnetic field values measured by the mobile terminal,        by delay parameters measured by the serving station when exchanging information with the mobile terminal, in order to determine the location of the mobile terminal.        
For instance, known systems and corresponding methods provide for a reference station (known as Mobile Location center) appropriately connected to the mobile network to identify, following a location request by a user or an authorised operator, the position of the mobile terminal based on predefined network parameters, for instance radio frequency power levels, TA (Time Advance), etc. coming from the mobile terminals themselves and/or from the serving station.
Among known methods, for instance, one can list the one described in the international publication N. WO0018148 in which the Radio Frequency (RF) information collected from the cellular phone (RF fingerprints or RF measurements of the cellular phone) are compared with RF information, contained in a reference database (reference RF fingerprints) and associated in bi-univocal fashion to elementary areas or pixels of the territory served by the network, and in which the location is performed assigning to the cellular phone the position corresponding to the reference RF fingerprint having the closest values to those measured by the mobile terminal.
A typical problem of known systems and methods is linked to the fact that the parameters necessary for location are available in a sure manner only during actual communications (busy state) between terminal and network, whilst they are not available in the case of absence of communications (idle state).
Because of this fact the locating operation, to be reliable, should be carried out only under conditions of busy state, since the parameters are reliable only under such conditions; however, this entails two additional problems.
First of all, since the parameters necessary for the locating operation, in the case of busy state, are available in sure fashion only at the stations or equipment belonging to the mobile networks, the retrieval of such information would require on each occasion specific interfaces between the reference station and the network equipment; as is well known, the management of the parameters necessary for the locating operation is different from one manufacturer of network equipment and the next.
Secondly, performing the locating operation under conditions of busy state would entail the occupation of precious network resources which, as is obvious, are preferably used to handle voice and/or data telephone traffic.
To overcome the problems described above, known locating systems are structured in such a way as to obtain the parameters necessary for the locating operation under idle state conditions.
However, this entails another problem, for although the parameters under idle state conditions can be retrieved from the mobile terminals without wasting precious network resources, such parameters, as is well known, are partial and generally transmitted in a manner that is partial and depends on the characteristics of the terminal so that the location thus obtained is substantially unreliable.
Moreover, known systems perform the locating operation under idle state conditions, assuming that the parameters necessary for the reference station to identify the position of the mobile terminals are always present and reliable, as if they were parameters obtained under busy state conditions.
Unfortunately in practice this is not true, so the locating operation conducted under idle state conditions generally yields results that only appear to be realistic.
In some cases, for instance, the mobile terminals present in the served area have mutually different characteristics, in terms of performance and quality, so the parameters necessary for the locating operations are made available to the reference station in a manner that depends on the characteristics of the terminal but, due to the intrinsic rigidity of such systems, they are processed in uniform fashion.
In this case, in accordance with the prior art, the locating operation yields more or less accurate results, as the characteristics of the mobile terminals change, but it is impossible for the user or for the operator to determine the situations of greater or lesser precision.
In other cases, the reference station has reference information that are not completely updated, for instance in regard to the characteristics of the base radio station, such as transmitted power, type of antennas, type of equipment, assigned frequencies, so that the locating operation conducted on the basis of reference information that are neither updated nor verified leads, due to the rigidity of the tools used, to completely wrong and unreliable results.
In this case, too, it is impossible for the user or the operator to determine the quality of the results obtained, since known locating tools do not allow to verify the characteristics of the reference information used.